Manufacture of cellulose derivatives



Patented Oct. 17, 1933 1,930,472. MANUFACTURE OF CELLULO'SE g DERIVATIVES Henry Dreyfus, London, England No Drawing, Original Application November "18, i

1930, Serial No. "496,572, and

in Great Britain.

December 18, 1929'." Divided and this applica A tion August 19, 1932 Serial No. 629,492 Q 1 Claims. c1, gee-1521' This application is a divisional application from my U. S." application S. No. 496,572 filed 18th November, 1930; which is a continuation in part of my prior U. S. application S. No. 492,363 filed th October, 1930.

The said U. S. application S. No. 492,363 describes inter alia the manufacture of new halogen containing cellulose ethers by replacing the hydroxy groups of hydroxy-containing cellulose ethers by halogen atoms, e. g. by treatment ,with thionyl chloride. The present invention is concerned with new methods for the preparation of these new halogemcontaining cellulose ethers.

According to the present invention halogencontaining cellulose ethers are prepared by reacting on cellulose or cellulose containing materials with reactants containing an etherifying atom or group and in addition at least one halogen atom. In particular I employ bodies containing an alkylene oxide group and a halogen atom, such as epichlorhydrin, or its homologues, such as brom-butylene oxide. In my U. S. Patent No. 1,502,379 I described a process for preparing ethers of cellulose from epichlorhydrin by causing the epichlorhydrin to react with the cellulose in presence of caustic soda. In this process the chlorine acts as the etherifying group, combining with hydrogen of the cellulose and splitting away as hydrochloric acid. I have now found that if the epichlorhydrin is caused to react in the substantial absence of alkali, halogenated cellulose ethers are produced. To obtain a high ether content the etherification may be conducted in two or more stages and use may be made of catalysts, for example copper powder, copper hydroxides or salts, to accelerate or further the etherification.

As starting materials cotton or other cellulosic materials or near conversion products thereof,

e. g. the regenerated type of artificial fibre or wood pulps, and preferably chemical wood pulps such as sulphite, sulphate or soda pulps containing substantially no lignin, pentosan, resin or like constituents may be used. Such cellulosic materials may be subjected to a pretreatment prior to the etherification. Such pretreatments may take the form of a simple treatment with organic acids, for example acetic acid or formic acid or a treatment with caustic or other alkali, or a treatment with mineral acids, for example sulphuric acid or hydrochloric acid or a combination of any of the above pretreatments may be applied. Mineral or organic acids may be, but need not be, substantially removed prior to the etherification and any strong alkali should also be ammonia. or with aliphatic, aromatic or. other organic amines to obtain amino-ethers of cellulose having an aflinit'yforacid dye'stuifs. For

P ,o Fries substantially (removed, for example by washing.

As described in my U. S. application S. No. 492,3 63'previously referred to, the halogen-containing ethers of'cellulo'se may be'treated with instance the halogen-containing cellulose ethers may be treated with ammonia, preferably under pressure, or may be boiled with an aliphatic or aromatic amine in presence of a solvent ornonsolvent diluent for the cellulose ether treated. For example, the halogen-containing ether may be heated in a closed container with excess of, concentrated ammonia solution at a temperature of 100 to 110 C. Alternatively the halogencontaining cellulose ether may be heated with excess of aniline under a reflux condenser for half an hour during which the mixture is boiled, after which the mixture is allowed to cool and the cellulose derivative is precipitated and washed with water.

The following example shows the best method known to me for carrying the invention into effect, but it is not to be considered as limiting the 789 invention in any way Example Wood pulp which has been treated with alkali and withformic or acetic acid according to my mixture of acetic acid with sulphuric or hydro- 1190 chloric acid is well washed, first with aqueous methylated spirit and then with absolute alcohol or methylated spirit. It is then allowed to steepv overnight in excess of epichlorhydrin. The N steeped mass is then gently refluxed with about 6-10 times its weight'of epichlorhydrinfor 4-8 hours or until a gain in weight corresponding with the formation of the required ether is obtained. Thus the cellulose may undergo an increase in weight of IOU-170%. The higher etherificationproducts are soluble in chloroform-alcohol.

What I claim and desire to secure by Letters Patent is:,

l 1. Process for the production oi -cellulose derivatives, comprising treating cellulose in the sub--- stantial absence of alkali with an etherifying agent containing in addition to the etherifying radicle a halogen atom of lower reactivity than said etherifying radicle, so that a halogen-containing cellulose ether is produced.

2. Process for the production. of cellulose derivatives, comprising treating cellulose in the substantial absence of alkali with an etherifying agent containing an alkylene oxide group and a halogen atom so that a halogen-containing cellulose etheris produced.

3. Process for the production of cellulose derivatives comprising pretreating cellulose with acid reagents and treating the products in the substantial absence of alkali with an etherifying agent containing an alkylene oxide group and a halogen atom so that a halogen-containing cellulose ether is produced.

rivatives comprising treatingcellulose with epichlorhydrin in the absence of alkali. so that a halogen-containing cellulose ether is produced. 5. Process for the production of cellulose derivatives comprising pretreating cellulosic material with acid reagents and then treating theproduct with epichlorhydrin in the absence of alkali so that a halogen-containing cellulose ether is produced.

6. Halogen hydroxy alkyl ethers of cellulose. 7. Chlorhydroxy propyl ether of cellulose.

8. Process for the production of nitrogen-containing cellulose derivatives, comprising treating cellulose in the substantial absence of alkali with an etherifying agent containing in addition to the etherifying radicle a halogen atom of lower reactivity than said etherifying radicle, so that a halogen-containing cellulose ether is produced, and then reacting the halogen-containing ether with a compound selected from the group consisting of ammonia and organic amines.

9. Process for the production of nitrogen-containing cellulose derivatives, comprising treating cellulose in substantial absence of alkali with an etherifying agent containing an alkylene oxide group and a halogen atom,yso that a halogen- 4. Process for the production of cellulose decontaining cellulose ether is produced, and then reacting the halogen-containing. ether with a compound selected'from the group consisting of ammonia and organic amines.

l0." Process for the production of nitrogen-containing cellulose derivatives, comprising treating cellulose with epichlorhydrin in the absence of alkali so that a halogen-containing cellulose ether is produced, and'then reacting the halogen-contair'iing ether with arcornpoundselected from the group consisting ofammoniaand organic amines.

HENRY DREYEus. 

